Geometric Control, Actuator Feasibility, and Algebraic Equilibria in a Four-Wheel X-Drive Robot
An analytical study of how a four-wheel X-drive robot can be controlled while respecting the geometry of motion and the constraints imposed by individual wheel actuators.
The problem
Omnidirectional robot motion is easy to describe with idealized velocities. The interesting part begins when each wheel has a finite speed range, sensing is imperfect, and the vehicle needs to converge to a desired pose.
My contribution
- Derived a wheel-speed map and characterized actuator-feasible chassis velocities for a symmetric X-drive.
- Used wheel effort to motivate a Riemannian metric on chassis motion.
- Formulated logarithmic pose-error feedback using the geometry of SE(2).
- Explored algebraic equilibrium structure and numerical motion cases.